Transformers and switches are widely used in modern radio frequency (RF) transceiver design to control signal flow. In a multi-port system, the combination of transformers and switches may establish signal flow between certain ports, while keeping other ports isolated. A widely seen example is the transformers plus the transmitter/receiver switch for antenna sharing in an RF transceiver. To enable multiple circuit blocks sharing the antenna, RF switches are put around transformers and antennas to control the antenna ownership by the circuit blocks. When the switch is in a first position, the antenna is connected to the transmitter, allowing the transmitter to send signals to a remote receiver. When the switch is in a second position, the antenna is connected to the receiver, allowing the receiver to receive signal sent by a remote transmitter.